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user6530
  • Member for 4 years, 5 months
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4 votes

Is it true that $\sum_{i=0}^{n-1} 2^i$ divides $\sum_{i=n}^{2n-1} 2^i$?

4 votes
Accepted

Compute $\iint _S (y^2+x^2)\, dA$ by change of variables.

4 votes
Accepted

Show that $\ker(\phi) \cong \mathbb{Z}^2$

3 votes

Predicate model that satisfies different formulas

2 votes

Prove that * is a binary operation

2 votes
Accepted

question about solution of $1,(x-5),(x-5)^2,...,(x-5)^m$ as a basis for $\mathcal{P}_m(\mathbf{R})$

2 votes
Accepted

Proving that a groupoid is a group, knowing the following properties

2 votes

Find $x,y,z$ satisfying $x(y+z-x)=68-2x^2$, $y(z+x-y)=102-2y^2$, $z(x+y-z)=119-2z^2$

2 votes

How to find the largest value of $n$ such that $S_n = \sum_{k = 1}^n (2k + 1) < 68$

2 votes
Accepted

I can't find where I make mistake in this "L'hospital like rule" derivation

2 votes

Which of the following statements about independent variables is correct?

1 vote

Finding a more efficient solution to a trigonometric identity problem.

1 vote

Proving that a non-empty subset of a vector space is itself a subspace iff it satisfies the closure axioms

1 vote
Accepted

confused about the definition of subgroup

1 vote
Accepted

Probability of specific event given two dice

1 vote

Let $0<\varepsilon <1$. Construct a set $E \subset [0,1]$ such that $E$ is dense in $[0,1]$ and for which $0<m(E)\le \varepsilon$.

1 vote

Give a regular grammar for L

1 vote

parametric equation of the circle in polar form with center different from origin

1 vote

Maclaurin series of $\frac{1}{\sqrt{4x^2 + 1}}$

1 vote
Accepted

Step in Understanding Mersenne Primes

1 vote
Accepted

Show that the following language is decidable

1 vote

How to solve $\int \frac{x^3}{(1+x)^5}\ dx$?

1 vote
Accepted

Is the linear transformation $T: P_{n} \to \mathbb{R}^{n+1}$ an isomorphism?

0 votes
Accepted

Finding $\iint_D e^{x+y} \,\mathrm{d}x\,\mathrm{d}y$ without substitution

0 votes

An example of two functions whose limits don't exist at a but the limit of their product does

0 votes

What is the formula for series like $-a1, -a2, +a3, +a4, -a5, -a6...$

0 votes
Accepted

Function f that has infinitely many superstable points

0 votes
Accepted

how to find if two elements can span a vector space

0 votes

How to reduce a quadric into canonical form without rigorous calculations?

0 votes

Why one cannot equate a sphere and a plane but a sphere with a sphere?